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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

Paperspace : a novel approach to document management by combining paper and digital documents

Sallam, Samer 20 November 2006 (has links)
Personal document management systems provide good support for storing and organizing digital documents. However, there are no computer tools that support organization of paper documents on our desks. We ran a study of people's organization of their office desk space with respect to their digital workspace. This study resulted in a set of requirements for a media bridging tool. Based on these requirements, we built a prototype media bridging tool called PaperSpace that uses computer vision to link paper and digital documents. The system also tracks piles of paper documents on the real desktop, and links those papers to digital documents stored in the computer. Digital documents can be sorted and grouped according to the physical layout of the corresponding papers on the desk. The system automatically creates digital piles of documents in a simulated desktop that reflect the paper piles on the real desktop. The user can access valuable information through the system, such as printing statistics, location of a printed document on the desk, and past projects and their documents. A two week user evaluation of the system showed interesting usage scenarios and future trends for improving user interaction.
312

Learning and Corporate Strategy: The Dynamic Evolution of the North American Pulp and Paper Industry, 1860-1960

Toivanen, Hannes 28 April 2004 (has links)
This study analyzes the long-term evolution of the North American pulp and paper industry, and offers a new synthesis of the dynamic forces that spearheaded the expansion and transformation of this large manufacturing industry. The evolution of the North American pulp and paper industry between 1860 and 1960 was driven by successive waves of technological learning that spawned structural change. Such waves transformed and expanded the sulphite and sulphate pulp, envelope, paper container, paper bag, magazine and printing paper, coated paper, board, and many other pulp and paper industries between 1860 and 1960. These waves repeated a pattern of co-evolution of technology and industrial organization that enveloped dynamic forces of change, such as innovation, corporate strategies, industrial relocation, and policy. As distinct branches of the pulp and paper industry passed from the early nascent phase to full maturity, the sources of innovation, nature of technological change, strategy and structure of leading firms, and industrial organization underwent throughout transformation. As these waves of industrial change passed from a nascent phase to maturity, the reciprocal dynamics between organization, corporate strategy, policy, and technological learning co-evolved, and established the evolutionary path of the North American pulp and paper industry.
313

New methods for evaluation of tissue creping and the importance of coating, paper and adhesion

Boudreau, Jonna January 2013 (has links)
The creping process and the conditions on the Yankee cylinder dryer are key factors in a tissue paper mill, and they therefore need to be kept under good control in order to maintain a high and uniform quality. To this end it would be valuable to be able to make on-line measurements of Yankee coating thickness as well as the crepe structure of the tissue paper. The adhesion of paper to the cylinder affects the creping process and more information about the parameters that affect the adhesion is therefore of interest. To perform trials on a full scale or in a pilot plant is very costly and laboratory creping equipment is therefore sought after in order to be able to measure the adhesion force. The coating layer for use on the cylinder was analysed. It contained a large amount of carbohydrates and could not be considered transparent. The thickness of the coating layer was measured on a laboratory cylinder with a method based on fluorescence. An optical brightener was added to the coating chemicals and the coating layer was subjected to UV-radiation. The intensity of the light emitted by the optical brightener was measured and gave an indication of the thickness of the coating layer. The equipment has to be further investigated before it is possible to implement the new sensor on-line. New creping equipment and an adhesion method were developed for use on a laboratory scale. The equipment can operate with different creping angles and the force needed to crepe the paper can be measured. The highest creping force was obtained for papers of high grammage, low dryness at adhesion, high drainability, high fines content and high hemicellulose content. A more direct method is to analyse the structure of the produced paper. Measurements were made on a tissue paper with an optical fibre sensor while the paper was travelling at low speed. The collected signal was mathematically analysed and the characteristic wavelength was calculated for different paper samples. These values were close to the wavelengths measured with an off line method by a commercial crepe analyser. / Baksidestext The creping process is the heart of tissue paper manufacture. To control the process better, on-line measurements of paper structure and coating thickness are sought after. The creping is highly dependent on the adhesion of the paper to the Yankee dryer. To be able to measure the adhesion, laboratory creping equipment was also required. Different pulp parameters affect the adhesion and some of them have been investigated in this work. The coating on the Yankee cylinder consisted mainly of fiber fragments and could not be considered as transparent, which had to be considered when choosing a method to measure coating thickness. A method based on the light emitted from an optical brightener in the coating when subjected to UV-irradiation was used, but has to be further improved before it can be used on-line. A new laboratory creping method was developed to determine the adhesion between paper and metal, and the force needed to scrape off the paper with a doctor blade was measured. The highest creping force was obtained for papers made of pulp with a high drainability, high fines content and high hemicellulose content. An optical method using reflected light to measure crepe wavelength on-line was developed. The paper travelled under a sensor and the light collected was mathematically analyzed to determine the most common wavelength.
314

Finding the Way Back Home : A study of Spatial Orientation, Navigation and Homing Behaviour in the Social Wasp Ropalidia marginata

Mandal, Souvik January 2017 (has links) (PDF)
For most of the animals, if not all, finding their way to a particular place is crucial for survival. To address this challenge of way-finding, different animals have evolved with different homing strategies. Social hymenopterans like honey bees, ants and wasps are of special interest – foragers of these insects show excellent homing capabilities while having simple neural resources. In this study field, honey bees and ants (desert ants, in particular) are among the most studied animals. Compared to these insects, our understanding on the homing mechanisms of social wasp is rather poor. For my thesis, I have studied homing behaviour of the tropical social wasp Ropalidia marginata, a predator in their foraging habit. To begin with, first I had to know their typical foraging range, which I found to be within about 500 m from their nest. Forager wasps possess a surprisingly well-developed familiarity with their foraging landscape, apparently more intricate than honey bees and desert ants. They acquire this spatial familiarity through flying around the landscape before starting foraging for food. Compared to honey bees and desert ants, this learning period in wasps appears to be much longer – this can be attributed to the much higher density of the tropical landscape in which they have evolved. I have also found that, if needed, they can fly to a distance of about 1.5 km for foraging and can return to their nest even if passively displaced to familiar and unfamiliar places. To return from unfamiliar places, they probably use some sort of searching mechanisms – a skill that they improve with their age. Such searching behaviour is prevalent throughout other hymenopteran insects. I conclude that capability and mechanisms of spatial orientation, navigation and homing in animals are much influenced by their evolutionary origin and the environment in which they have evolved.
315

Modificação quimica do amido de mandioca e estudo de sua aplicação em revestimento couche

Taparelli, Jesus Roberto 02 January 2005 (has links)
Orientador: Lucia Helena Innocentini Mei / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-04T05:33:53Z (GMT). No. of bitstreams: 1 Taparelli_JesusRoberto_M.pdf: 3122835 bytes, checksum: 2a962c8596eae20801290e744716b2cf (MD5) Previous issue date: 2005 / Resumo: Neste presente trabalho, foi estudada a grafitização de N-metilol acrilamida em amido de mandioca nativo, em meio aquoso, com proporções de 20, 30 e 40% em relação ao peso de amido, tendo como objetivo avaliar a aplicação técnica do produto resultante em formulações de tintas de revestimentos couché, aplicado sobre uma superficie de papel cartão. Estes novos polímeros, bem como o amido de mandioca e o amido de milho nativo, foram caracterizados por: (i) Análise Dinâmico-Mecânica (DMA), onde se conseguiu verificar moderadas modificações nas transições térmicas; (ii) Espectroscopia na região do Infravermelho(FT_IR); (iii) Microscopia Ótica (MO) e (iv) Microscopia Eletrônica de Varredura (MEV), onde percebeu-se mudanças morfológicas nos grânulos de amido modificado, que se apresentaram maiores que os do amido nativo. Para uma análise do comportamento destes polímeros em formulações de tintas de revestimentos couché, foi utilizado como referência padrão o látex de estireno-butadieno carboxilado, atualmente utilizado na indústria de papel, como ligante (ou resina) principal. Nas tintas de revestimentos couché desta tese, foram analisadas as aplicações feitas em papel cartão revestido, onde se utilizou para teste de imprimibilidade as seguintes análises: Pick teste seco; Pick teste úmido; alvura; teste de absorção superficial - K & N; brilho de impressão; rugosidade e absorção de óleo. Um bom revestimento deverá apresentar uma boa adesão à superficie do papel, evitando seu arrancamento do mesmo. Dos testes de arrancamento, todas as amostras dos revestimentos feitos com amido de mandioca, modificados com Nmetilol acrilamida, apresentaram excelentes resultados / Abstract: In this work, it was studied the graftization of native tapioca starch with of Nmethylol acrylamide (NMA) in aqueous media, at several proportions (20, 30 e 40%) relative to the starch weight, with the aim to evaluate the technical application of the product obtained in inks formulations used for finishing covering, applied over paper-card surfaces. The NMA and the native starch, as well as the starch derivatives, were characterized by: (i) Dynamic Mechanical Analysis (DMA), which showed mild modifications in the thermal transitions; (ii) lnfrared Spectroscopy (F_TIR); (iii) Oplical Microscopy (OM) and (iv) Electron Scanning Microscopy (SEM) which revealed morphological changes in the starch grains, being the modified starch grains bigger than those native. To analyze the behavior of these polymers in formulations of inks, used for finishing covering (known as couché paper card), it was utilized latex of styrene-butadiene - carboxylate as reference, current1yused as binder in the paper industry. For the paper card with the finishing covering it was utilized tests of printability as: dry pick test; wet pick test; whiteness; K and N test; shine of impression; roughness and oil absorption. In the printing process, the graphic ink used presents tacking that is responsible for a perpendicular force to the surface of the paper, which is able to peel its covering. The peeling tests done with the formulations modified with modified tapioca starch with Nmethylol acrylamide (NMA) presented very promising results / Mestrado / Ciencia e Tecnologia de Materiais / Mestre em Engenharia Química
316

Modification of Paper into Conductive Substrate for Electronic Functions : Deposition, Characterization and Demonstration

Montibon, Elson January 2011 (has links)
The thesis investigates the modification of paper into an ion- and electron-conductive material, and as a renewable material for electronic device. The study stretches from investigating the interaction between the cellulosic materials and the conducting polymer to demonstrating the performance of the conductive paper by printing the electronic structure on the surface of the conductive paper. Conducting materials such as conducting polymer, ionic liquids, and multi-wall carbon nanotubes were deposited into the fiber networks. In order to investigate the interaction between the conducting polymer and cellulosic material, the adsorption of the conducting polymer poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonate) (PEDOT:PSS) onto microcrystalline cellulose (MCC) was performed. Electroconductive papers were produced via dip coating and rod coating, and characterized. The Scanning Electron Microscopy (SEM) / Energy Dispersive Spectroscopy (EDS) images showed that the conducting polymer was deposited in the fiber and in fiber-fiber contact areas. The X-ray Photoelectron Spectroscopy (XPS) analysis of dip-coated paper samples showed PEDOT enrichment on the surface. The effects of fiber beating and paper formation, addition of organic solvents and pigments (TiO2, MWCNT), and calendering were investigated. Ionic paper was produced by depositing an ionic liquid into the commercial base paper. The dependence to temperature and relative humidity of the ionic conductivity was also investigated. In order to reduce the roughness and improve its printability, the ionic paper was surface-sized using different coating rods.  The bulk resistance increased with increasing surface sizing. The electrochemical performance of the ionic paper was confirmed by printing PEDOT:PSS on the surface. There was change in color of the polymer when a voltage was applied. It was demonstrated that the ionic paper is a good ionic conductor that can be used as component for a more compact electronic device construction. Conductive paper has a great potential to be a flexible substrate on which an electronic structure can be constructed. The conduction process in the modified paper is due to the density of charge carriers (ions and electrons), and their short range mobility in the material. The charge carrying is believed to be heterogeneous, involving many charged species as the paper material is chemically heterogeneous. / <p>Fel ordningsnummer (2010:28) är angivet på omslaget av fulltextfilen.</p> / Printed Polymer Electronics on Paper
317

Studium vlivu zvýšené teploty na vlastnosti papíru v inertní atmosféře / Study of the elevated temperature influence on paper properties in the inert atmosphere

Novotná, Martina January 2009 (has links)
This diploma thesis was aimed at study of the effect of various gaseous extinguishing media in an environment of increased temperature on the paper and its properties. Paper samples were exposed to elevated temperature in air, CO2 gas and gas mixtures of N2:Ar (1:1). The impact of conditions on the mechanical, chemical and optical properties of paper has been studied after exposure of the paper by extinguishing media under elevated temperature. The change of properties was determined immediately after exposure of samples under simultaneous conditions of fire, further one was determined for samples exposed to conditions of dry and wet aging. As a reference sample was used crude paper. Values of elasticity modulus, strength tensile, tearing resistance, the work needed for break tension, the total color difference and pH of samples have been determined. The results showed that every external influence causes at least some change in mechanical, optical and chemical properties such as increased temperature, the effect of extinguishing media or ageing of paper. The gas mixture N2:Ar (1:1) had the smallest influence on the sample paper, which was worked. Thus this gas mixture could be the best choice for the application in archive environments.
318

Development of Substrate-based Ambient Ionization Techniques for Direct Sampling by Mass Spectrometry

Jackson, Sierra January 2021 (has links)
No description available.
319

Paleoenvironment and Lateral Extent of an Exposed Carbonate Build-up: Horry County, South Carolina

Raterink, Lisa A. 02 October 2008 (has links)
No description available.
320

Stabilisation of high-yield pulp against photo-induced discolouration

Quiddington, Christopher John January 2001 (has links)
No description available.

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